The term “relatively high bit depth” as used herein may refer to a bit depth of a codeword space such as 11 bits of a 11-bit codeword space, 12+ bits of a 12+ bit codeword space, and so forth, that are higher than a relatively low bit depth such as 10 bits of a 10-bit codeword space, 9-bits of a 9-bit codeword space.
Different codewords mapped from pre-reshaped images may be collapsed into the same value or the same codeword in forward reshaping operations at an upstream device. Textual variations and image details represented in the pre-reshaped images may be lost in forward reshaped images. In addition, the pre-reshaped images themselves may already have banding artifacts before the forward reshaping operations. When a recipient system generated decoded images corresponding to the forward reshaped images, banding/contouring artifacts often occur in display images as a result of many-to-one mappings in the forward reshaping operations as well as the banding artifacts already existing in the pre-reshaped images.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.